A User is a human being who operates a computer in the real world. However, on the other side of the screen, there is a micro-civilization of humanoid computer programs, created by users. If a user writes and compiles a program on his computer, the program will look exactly like his user counterpart in the digital world, although in some non-canon cases this is not always the case (as Mercury's user in TRON 2.0 turns out to be Alan Bradley). Users are looked upon by many programs as akin to gods.

Sam Flynn, the son of Kevin Flynn

A user can enter into the digital world through the extremely experimental method of digitization, where they get hit by a dual laser beam from a digitizing gun and literally disintegrate. The laser beam collects every atom of the user and converts the physical form of the human into digital data. Through this process, the user is transported into the digital world and can interact with the computer programs physically. Users have experienced dizziness and disorientation upon entry into digital worlds.

If something is wrong with the digitization software/hardware, then the user may become corrupted during the transfer from the real world to the digital world.

Users have special abilities beyond the capabilities of basic programs when in a digital environment. They can regain and regenerate more energy than programs, transfer their energy to programs and other objects, withstand much more damage than programs and have more complex data than programs. If a user is derezzed in the computer world, he will not die but simply be kicked out of the system and reform back to the real world via the digitizing gun. However, if the digitizing software/hardware is unavailable or the digitizing gun is broken, then the user will die if he is derezzed.

Although it is not confirmed nor denied, there is the possibility that Lora Bradley, Jet's mother, was digitized also. This is inferred due to emails within the TRON 2.0 game.

Lora died due to a misfire of the digitizing laser. If this was active, it can be assumed that she was digitized or partially digitized.

Emails detail rumours that Alan Bradley may have incorporated parts of Lora inside the computer after the digitizing accident into her program, Ma1a (Later Ma2a and Ma3a)

Ma2a exhibits traits recognised as Lora's, suggesting she is connected with it somehow. There is no specific answer to this possibility is provided one way or the other, and alternatives to this are also detailed in the plot mechanisms within TRON 2.0.